IADO   05364
INSTITUTO ARGENTINO DE OCEANOGRAFIA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Climate and phytoplankton development in an Antarctic coastal area
Autor/es:
SCHLOSS I.R.; DUMONT; SARAVIA; HERNANDO ; MICHAUD TREMBLAY; GARCIA M.; HOFFMEYER M.; FERREYRA
Reunión:
Congreso; XIth SCAR Biology Symposium; 2013
Resumen:
Climate and phytoplankton development in an Antarctic coastal area Potter Cove is a glacier-influenced coastal environment located on King George Island, West Antarctic Peninsula. In such environment, the rise in air temperature contributes to decrease the surface salinity, increase the water stability and increase the amount of particles of terrigenous origin. This in turn affects the light field and the Sverdrup critical depth. When combined to the typically intense wind-generated turbulent mixing in the area, the formation of phytoplankton blooms in the area is usually precluded. In January 2010, an unprecedented phytoplankton bloom was observed in the area in association with particularly cold air temperatures. Here 1) we formalize and improve a conceptual model that relates the light-mixing conditions to phytoplankton accumulation; and 2) we use an information-theoretic model approach to relate maximum observed phytoplankton concentrations to seasonally averaged air temperature over a 20-year time series. Our results support the idea of a regime shift, in which either bottom-up or top-down processes prevail along a gradient of air temperature values, allowing or not for the accumulation of large phytoplankton. In the high temperature range, which is the most probable future scenario over the next century, the formation of blooms would probably be less frequent due to both inadequate physical conditions and more efficient micro- and mesozooplankton grazing.